Pressure-sensitive light-extracting paper

ABSTRACT

A pressure-sensitive light-extracting drawing surface including a light guide operable to receive a light source, wherein light is extracted from a light guide when pressure is applied to the drawing surface by a marking instrument. A resultant light-emitting drawing can be erased or can be made permanent. An optional multi-layered film disposed on the light guide allows drawings to be created in fluorescent, luminescent, phosphorescent, or photochromic colors. A background sheet containing designs may be inserted behind the light guide. The drawing surface can be embodied as a pressure-sensitive light-extracting “paper.” The invention may be embodied as a drawing tablet, a drawing tablet add-on to a modular graphic display device, or a toy drawing tablet for tracing alphabets, numerals, and characters from comic books, cartoons, and movies.

CROSS REFERENCE TO RELATED APPLICATIONS

U.S. patent application No. 10/939,203 titled “Modular Graphic DisplayDevice” filed on Sep. 10, 2004.

COPYRIGHT NOTICE

A portion of the disclosure of this patent document contains materialthat is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in the Patent and TrademarkOffice patent file or records, but otherwise reserves all copyrightrights whatsoever.

Copyright 2004, Donahue Labs, Inc.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to drawing and writing devices. Morespecifically, the invention relates to illuminated drawing surfaces,tablets, and boards.

2. Description of Prior Art

Drawing and writing tablets and boards have existed for generations.Examples include chalk boards, white boards, mechanically-aided drawingdevices, clipboards with side or back illumination, magnetic drawingtablets, fluorescent ink pens, luminescent tablets, phosphorescenttablets, thermochromic tablets, and pressure-sensitive tablets usingplastic film and wax. There are several patents that discuss suchtablets and boards for drawing and writing.

U.S. Pat. No. 3,279,100 issued to Knott and titled “Exhibitor ofInformative Markings Removably Applied by Pressure to a Display SurfaceThereof”, discloses a pressure-sensitive drawing tablet using multiplelayers of wax and plastic which allows displays in color by shifting abacking surface printed with a grid of red, yellow, and blue squares.The drawing tablet, however, is not illuminated.

U.S. Pat. No. 3,579,871 issued to Eddington and titled “Record book”,discloses in the Abstract: “A record book comprising a plurality ofleaves wherein each leaf is centrally divided in the transversedirection with separate writing sections located on each side of thedivision. Each writing section includes a series of longitudinalseparate writing spaces, each space having a wax backing with an opaquewriting strip covering the backing and a clear plastic outside coverover the writing strip. The writing strip of each space can be removedfrom in contact with the wax backing. The stylus is to be retained whennot in use within a hinge connection which maintains the entire book inthe closed, not-in-use position.” This record book uses multiple layersof wax and plastic allowing different sections of writing to beseparately erased. This record book is not illuminated.

U.S. Pat. No. 4,051,609 issued to Boursaw and titled “Method of MakingReusable Writing Board and the Product Thereof”, discloses in theAbstract: “A reusable writing board of ‘slate board’ is both improvedand of lower cost, avoiding use of the usual separate black-cardboardpiece stapled to a backing. In a single printing operation, which isneeded for face-printing anyway, the ‘slate’ or background surface isprovided on the same piece of paperboard. After further machine steps, afinal operation of gluing and folding produces the finished slate boardwith a decoratively-printed head panel glued to extend down protectivelyover the top edge of the plastic work sheet covering the printedbackground. If desired, educational or informative discs can berotatably secured under the head fold. Also, if desired, an air pocketcan be formed under the head fold such that after writing by impressionsthrough the work sheet, a sudden slap on the cover of the air pocketwill raise the work sheet pneumatically to erase the writing.” Thismethod describes an improved manufacturing process for producing areusable writing board using multiple layers of wax and plastic allowingerasure with a slap on the cover of the board. The writing board,however, is not illuminated.

U.S. Pat. No. 4,590,381 issued to Mendelson and titled “PhosphorescentMarking System”, discloses in the Abstract: “A device of phosphorescentmaterial on which luminescent images are formed and retained for aperiod of time is disclosed. The device includes phosphorescent materialin the form of a sheet mounted on a support. The support exposes the topsurface of the phosphorescent material to activating light. A shieldmaintains deactivation of the phosphorescent material. Upon removal ofthe shield in a dark area, the phosphorescent material may be activatedin selected areas to form an image which is retained for a period oftime until the phosphorescent material has decayed to an inactivatedstate of imperceptible level of luminescence. This type of device isparticularly suited to amusement and educational items for children.However, it is also useful in industrial applications where writing andcommunication of information in the dark is necessary.” The markingsystem describes using a light pen to form an image on a sheet ofphosphorescent material. A shield that blocks light of the activatingwavelength of the phosphorescent material is placed above the sheet toensure that the sheet remains in a deactivated state, or, in the eventthat the sheet has been activated, that the deactivation of thephosphors proceeds unperturbed. The system can only be used in a darkarea, requires a light pen, and involves constant covering anduncovering of the phosphorescent sheet.

U.S. Pat. No. 4,888,874 issued to Oster and titled “Drawing DeviceHaving Mobile Stylus Tracing Lines on Glass Plate”, discloses in theAbstract: “A toy drawing device in which a window in a housingcontaining powder is covered by a glass plate whose edges are receivedwithin a groove in a sectioned rim joined to a window frame to preventleakage of powder therefrom. A mobile stylus under the control of anoperator acts to trace lines on a layer of powder adhering to theundersurface of the glass plate. To prevent injuries should the glassplate break, its outer surface is shielded by a transparent protectivefilm formed of heat-formable, synthetic plastic material.” Amechanically-controlled stylus is used to trace lines on the undersideof a glass screen to which a powdered substance adheres. The glassscreen is shielded by a transparent protective film to prevent injurydue to a break in the glass. The device, however, is not illuminated, isbulky and heavy, and is expense to manufacture.

U.S. Pat. No. 4,927,748 issued to Kinberg and titled “LuminescentWriting or Display Device”, discloses in the Abstract: “A display orwriting slate capable of producing luminescent images upon theapplication of pressure thereon which can be readily erased andrepeatedly used that includes a pair of over-lying sheets, one of whichis translucent or transparent, containing a luminescent dye or pigmentand the other of which is opaque, and which sheets have a smooth surfaceat their interface. At least one of the sheets is formed of a pliableplastic with its interface surface tending to adhere to the interfacingsurface of the other sheet when a pressure is applied thereto to producethe luminescent images. The improvement resides in the incorporation ofa non-migrating dye or pigment in the translucent or transparent sheetso as to resist the migration of the luminescent dye or pigment from thetranslucent or transparent sheet to the interface surface of the othersheet.” This patent describes a writing device where pressure from astylus onto a translucent sheet containing a luminescent dye produces aluminescent image. While the device displays an image throughluminescence, the device does not allow for enhanced color, brightness,and contrast.

Japanese Pat. 03248151A issued to Takeshi et al. and titled “Method forWriting and Erasing Using Photochromic Board and Photochromic Board forthe Purpose”, discloses in the Abstract: “To allow writing and erasingto and from a photochromic board from a distant position by irradiatingthe photochromic board with a beam for a 1 ^(st) wavelength to allow thephotochromic material to develop a color and to write characters, etc.,and casting hot air or light of a 2 ^(nd) wavelength to the colordeveloped part to erase the written characters, etc.” The writingsurface of the board contains a photochromic compound and the writinginstrument is a wand that emits light of activating and deactivatingwavelengths of the photochromic compound. The device uses a beam oflight from a wand to create characters in photochromic color, but doesnot allow for enhanced color, brightness, and contrast.

U.S. Pat. No. 5,083,242 issued to Piotrowski and titled “IlluminatedUnderwater Writing Tablet”, discloses in the Abstract: “An illuminatedunderwater writing tablet having an elongated tubular lightsourcehousing and an elongated tablet sheet of Plexiglass material. Thelightsource housing has an elongated slot in its bottom surface thatreceives the top edge of the tablet sheet. A chemically activated lightstick is removably stored in the light source housing and when it isactivated it will illuminate the tablet sheet by directing light throughits interior. A grease stick is tethered to one end of the lightsourcehousing. An end cap is tethered to the other end of the lightsourcehousing.” This writing tablet describes a plastic tablet sheet, atubular light source housing, a chemically activated lightstick storedin the housing, and a grease pen. The writing tablet displays an imagethrough a chemically activated lightstick.

U.S. Pat. No. 5,321,891 issued to Arad et al. and titled “DrawingDevice”, discloses in the Abstract: “This invention relates to anapparatus for writing or drawing that is characterized by an enclosedcase having a front side and a back side and in which the front sideconsists of a transparent screen. Disposed within a substantiallyrectangular case is a slightly adhesive powder which adheres to theundersurface of the transparent screen so as to render it opaque. Afirst and second stylus is mounted within the case for producingrelatively thick and relatively thin lines by movement along theundersurface of the transparent screen in a manner for removing theadhesive powder and to thus produce lines. The first and second stylusare both moved in the X and Y coordinates through the use of externalhorizontal and vertical line control knobs which are internally coupledto the multiple stylus by first and second transverse rods, each beingsupported on and attached to a separate cable loop system. The multiplestylus may be fixedly withdrawn from the screen by actuation of theretraction thus enabling the operator to use both hands for moving thestylus to a second horizontal and/or vertical position on the screenwithout production of a line from the first to the second writing ordrawing.” Two mechanically-controlled styluses are used to trace thickand thin lines on the underside of a transparent screen to which apowdered substance adheres. The powder lines can be erased by gentlyshaking the drawing device. The device is not illuminated, and is bulky,heavy, and expense to manufacture.

U.S. Pat. No. 5,324,202 issued to Meyers et al. and titled “LuminescentDisplay and Copying Apparatus and Method for Using Same”, discloses inthe Abstract: “An apparatus and method for providing a luminescentdisplay by applying pressure to a transparent planar sheet containing aluminescent dye or pigment where such pressure is sufficient to causeone smooth surface of the transparent sheet to contact a facing smoothsurface of an opaque planar sheet, the smooth surfaces of thetransparent and opaque sheets tending to adhere together at the area ofcontact, thereby creating a luminescent image at the area of contactwhich can be selectively erased by separating the smooth surfaces of thetransparent and opaque sheets at the area of contact, and for allowingcopying of the image by positioning a sheet of carbon paper between theopaque sheet and a sheet of plain paper so that the application ofpressure to the transparent sheet causes pressure to be applied throughthe carbon paper to the sheet of plain paper, thereby copying the imagedisplayed on the transparent sheet onto the sheet of plain paper, thecarbon paper being selectively movable to allow segments of carbon paperwhich can produce images of different colors to be positioned betweenthe opaque sheet and the sheet of plain paper during the drawing of animage to facilitate the production of a multi-colored copy of thedisplayed image, the apparatus allowing the use of different sizes andmultiple sheets of plain paper and providing means for ejecting suchpaper from the apparatus.” The apparaus displays an image throughluminescence only, and does not allow for enhanced color, brightness,and contrast.

U.S. Pat. No. 5,368,489 issued to Confalone et al. and titled“Luminescent Display Device”, discloses in the Abstract: “A luminescentwriting or display device and method of manufacturing the same whichincludes a transparent vinyl sheet containing a fluorescent or neon dyeand an opaque sheet made from coated paperboard stock. An acrylic resinvarnish is provided on a portion of the paperboard stock for forming acontact surface with the vinyl on which an image may be created byapplying pressure thereto. The image is readily erased by separating thesheets. Another portion of the paperboard stock receives printing inksfor providing a permanent ink display on a header portion of the device.The device may be manufactured in a continuous process at a reducedcost.” The device displays an image through luminescence only, but doesnot allow for enhanced color, brightness, and contrast.

U.S. Pat. No. 5,441,418 issued to Brown and titled “ThermochromicDrawing Device”, discloses in the Abstract: “A thermochromic drawingdevice is disclosed which can be marked and erased by selectivelychanging the temperature of its drawing surface. The drawing surface ofthe drawing device consists of a flexible substrate printed withthermochromic inks having at least two color states. The flexiblesubstrate has low thermal mass thereby enabling it to readily assimilatetemperatures induced by a user and, consequently, facilitating thetransition of the thermochromic inks from one color state to another.The drawing surface is further provided with an insulating layer whichisolates the flexible substrate from unwanted heat sinks and heatsources thereby preventing unwanted color transitions of thethermochromic inks. Thus, a user can selectively change the color stateof portions of the drawing surface to create distinctive markings.” Thedevice comprises of a substrate coated with thermochromic inks, a heatinsulating layer underneath the substrate, and a pen containing acooling substance and a heat conducting tip. The cool tip of the pen incontact with the thermochromic substrate creates the drawing, which canbe erased by the user placing his hand over the drawing. The devicedisplays an image through thermochromic inks only, and does not allowfor enhanced color, brightness, and contrast through illumination.

Japanese Pat. 07314981A issued to Kazuo and titled “Display Board andWriting Instrument for Display Board”, discloses in the Abstract: “Toerase a part to be deleted in a single tracing pass by making the lightprojection width of a deletion pen larger than the light projectionwidth of a writing pen, using a writing sheet of a photochromicmaterial.” A photochromic writing tablet is used with a writing pen anda deletion pen. The writing pen emits a UV light that activates thephotochromic material, whereas the deletion pen emits white light thaterases the photochromic writing. The tip of the deletion pen is widerthan the tip of the writing pen, thereby allowing the deletion pen toerase a line of writing with one stroke. The device uses alight-emitting pen of activating wavelength to create characters inphotochromic color only.

U.S. Pat. No. 5,607,223 issued to Brotz and titled “IlluminatedClipboard with Movable Writing Surface”, discloses in the Abstract: “Anilluminated clipboard for use by a seated individual in darksurroundings with structure to attach the clipboard to a leg of theuser, such clipboard having a light-emitting body in one embodiment withmeans to illuminate therethrough utilizing a sheet of illuminatedmaterial disposed thereunder and a translucent roll of film or paper ona spool which is passed from a storage roller to a take-up roller overthe active writing surface of the light-emitting planar surface inimmediate contact therewith such that indicia or writing thereon isvisible to the user by backlighting from the underlying illuminatedplanar body.” A clipboard with a contoured back is attached to a leg ofthe user for writing using a pencil or pen on a translucent sheet. Thesheet is illuminated by a backlighting panel, but is not erasable.

U.S. Pat. No. 5,938,449 issued to Masson and titled “Reusable WritingBoard with Locking Function”, discloses in the Abstract: “A pressuresensitive reusable writing board is provided which includes a backingmember that includes an upper section that folds down over the lowersection that accommodates the wax layer and polyester writing sheet. Asa result, the upper section provides a protective cover for the lowersection. A distal edge of one of the upper or lower sections includes aloop which is in registry with a slot disposed in the distal edge of theother of the upper or lower sections. As a result, when the board isfolded together to assume a closed position, the loop may be foldedforward through the slot disposed in the opposing section or panel andthe stylus may be inserted through the loop to lock the board into aclosed position. As a result, any writing or artwork made on thereusable writing surface can be preserved while the board is beingtransported or handled.” The writing surface consists of a wax layercovered with a polyester film. Pressure from a stylus on the polyesterfilm creates a drawing that is not illuminated.

U.S. Pat. No. 6,092,294 issued to Mak and titled “Drawing Board”,discloses in the Abstract: “A drawing board having a body and agenerally transparent screen on the body. The screen has front and rearsides and contains a viscous opaque liquid and iron dust in the liquid.A magnetic eraser is movable within the body between a rest positionaway from the rear side of the screen and an operating position againstthat rear side for operation to move, through magnetic attraction, theiron dust away from the front side of the screen such that the iron dustbecomes invisible on the screen. A spring biasses the eraser towards therest position. A pen having a magnetic tip is used to draw on thescreen.” The drawing board is not illuminated and requires amagnetically tipped pen.

U.S. Pat. No. 6,113,150 issued to Kinberg and titled “LuminescentWriting Display Device Having Protective Layer”, discloses in theAbstract: “A writing and display device for producing luminescent imagesupon application of pressure thereon which can be readily erased andrepeatedly used having a protective layer to prevent damage to thewriting surface thereof. The device includes a backing member with asmooth surface over which a translucent or transparent sheet containinga luminescent dye or pigment and an opaque pliable plastic sheet aredisposed. At least one of the sheets is formed of a pliable plastic withits interface surface tending to adhere to the interfacing surface ofthe other sheet when a pressure is applied thereto to produceluminescent images. A pliable, transparent protective sheet is disposedadjacent to and coextensive with the translucent or transparentluminescent sheet. Upon application of pressure onto the protectivesheet, which pressure is transmitted to the luminescent sheet by virtueof the pliability of the protective sheet, the interfacing surfacesadhere to each other to thereby produce a luminescent image.” Thispatent describes a pressure-sensitive luminescent sheet. A pliabletransparent sheet is placed above the luminescent sheet to preventpuncture and damage to the luminescent sheet from the stylus. Comparedto the present invention, this device displays an image throughluminescence only on a pressure-sensitive sheet, and does not allow forenhanced color, brightness, and contrast.

U.S. Pat. No. 6,578,615 issued to Bronson and titled “Magic SlateCapture and Display Device”, discloses in the Abstract: “A device forforming erasable images on a reusable medium, comprising: an erasingportion; and a writing portion; wherein the erasing portion comprises aseparator for separating at least two layers of the reusable medium; andwherein the writing portion comprises automatic machine-driven pressureapplicators for applying pressure but no ink to the reusable medium,thereby forming an image on the reusable medium.” The display device isnot illuminated and is intended primarily for use as acomputer-controlled printer.

U.S. Pat. Application 2003/0112623 by Yu Sun et al. and titled“Ultraviolet Light Writing System”, discloses in the Abstract: “Anultraviolet light emitting diode flashlight is contained within ahousing having a pen tip extending from the housing and an ink or dyereservoir in fluid communication with the pen tip. The ultraviolet lightemitting diode flashlight within the housing emits light capable ofinducing fluorescence in the ink or dye. A switch assembly completes anelectrical circuit between a light emitting diode and a battery toactivate the flashlight. A writing system package includes at least twoof: a neon or pastel colored writing surface, a security pen having anink or dye that fluoresces in the visible portion of the light spectrumupon exposure to ultraviolet light, and an ultraviolet light emittingdiode flashlight.” The system allows visualization of writing ininvisible ink during writing, but requires a special fluorescent ink,and the writing is not erasable.

Japanese Pat. 2003222971 issued to Hiroyuki et al. and titled “Methodfor Displaying Multicolor Image, and Multicolor Image Display”,discloses in the Abstract: “To provide a method for displaying amulticolor image and a multicolor image display excellent in resistanceto repeated image writing and erasure with light and having good colorsof an image” The multicolor image display device uses photochromiccompounds as the display media and LED arrays of different activatingand deactivating wavelengths. Arrays of LEDs activate and deactivate thephotochromic compounds, but the device does not allow for enhancedcolor, brightness, and contrast.

U.S. Pat. No. 6,666,742 issued to Koizumi and titled “Controlling LightDischarged by a phosphorescent Material”, discloses in the Abstract: “Amaterial that phosphoresces may be controlled and the phosphorescencemay be terminated when desired. A phosphorescing material may be exposedto an energy source that causes the material to stop phosphorescing.Thus, a pattern may be written on a surface, which is phosphorescingusing a coherent energy source. The written pattern, represented bydarkened regions, may be recognized by users as a symbol, a graphics ortext.” The device displays an image on a phosphorescent background, butdoes not allow for enhanced color, brightness, and contrast.

U.S. Pat. No. 6,722,891 issued to Ma and titled “Magnetic Drawing BoardApparatus” (Ma Apr. 20, 2004) discloses, in the Abstract: “A magneticdrawing apparatus including image forming means, image erasing means,motion generating means, movement control means and a main housing,wherein: the image forming means include a plurality of magnetic cellswhich collectively define an image forming surface, the magnetic cellcontains a viscous fluid and magnetic powder; the image erasing meansinclude a magnetic image eraser which is adjacent to the image formingmeans, the magnetic image eraser is connected to the motion generatingmeans and is movable relative to the image forming means; and themovement control means include means for actuating the motion generatingmeans and means for selecting the direction of movement of the magneticimage eraser with respect to the image forming means.” The drawing boardis useful and interesting for children, but the board is notilluminated.

What is needed, therefore, is a drawing and writing paper that overcomesthe above-mentioned limitations of the prior art and that: (1) providesbright light-emitting drawings and writings, (2) provides easy-to-readdrawings and writings in single or multiple colors, (3) uses a stylus orequivalent pressure-applying device as the marking instrument, (4) iserasable or permanent, (5) is easy to operate, (6) allows for easyinsertion of background colors and designs, (7) can be used under day ornight lighting conditions, (8) is multipurpose (e.g. toy, bulletin boardor white board, used in the dark, under water, in harsh environments),(9) is waterproof, (10) is thin and lightweight in construction, (11) isinexpensive to manufacture.

BRIEF SUMMARY OF THE INVENTION

The present invention includes a pressure-sensitive paper, film, orcomposite to extract light from a light guide. The invention enables auser to draw or write on a film, covering a light guide, using aninkless stylus. Alternatively, the invention also enables a user to drawon a light guide that will change its shape to include light reflectingangles upon application of pressure, resulting in emission of light.Light emission, via extraction or reflection, provides color,brightness, and contrast needed to create lines of light in a drawing orwriting. The light extracting film works when a user applies styluspressure to a film and binds a bottom surface of the film to anunderlying light guide or backlight creating a light emission notch. Thenotch transmits light to a diffusing surface on the film which emits thelight, providing the effect of writing in light. The lighted image ortext remains as long as the film is in contact with the light guide. Thelighted image or text is erasable by separating the film from the lightguide. In the alternative version of the invention, pressure is appliedto a light guide that includes light reflecting angles that emit light.

The film or paper can by made using any of several materials orcombinations of materials. The film may contain transparent orsemi-transparent pigments, transparent or semi-transparent dyes,fluorescent compounds, luminescent compounds, phosphorescent compounds,photochromic compounds, and opaque filters (halftones). Materials can bevaried for desired clarity or effects.

The pressure-sensitive material can be embodied in rolls, sheets, pads,or single sheets of the light guide “paper” or media. A pad of paperwith multiple sheets can use an insertable rigid plate, for separatingsheets, to prevent pressure applied to underlying sheets. Anotherexample is a toy drawing tablet for drawing, writing and/or tracingalphabets, numerals, and drawing upon themed backgrounds.

The light guide design allows use of the latest advances in plasticlight guide design and LED technology. Furthermore, the design of thisinvention allows for low cost manufacturing through the use of plasticinjection molding and high-flux LEDs.

The present invention can be used as a toy and in many commercial andmilitary applications such as drawing and writing on a bulletin board orwhite board, in the dark, under water, and in harsh environments.

Features and Advantages

Recent advances in semiconductor light sources, including thedevelopment of high-flux and low-cost light emitting diodes (LEDs),together with advances in light ray modeling and plastic injectionmolding, have resulted in the development of low-cost devices forguiding light to the surface of a display and for providing backlightingto a transparent or semi-transparent image. The present invention usesthe principals of light wave propagation, including Total InternalReflection, to create drawings or writings on a pressure-sensitivetablet by extracting light from a light guide or by permitting light tobe transmitted from a backlight.

A feature of the present invention is that it can provide eitherpermanent or erasable, bright or dull light-emitting, or high contrastdrawings and writings. This is achieved by combining a light guide orbacklight with a pressure-sensitive light-extracting or light-blockingfilm. High-flux or low-flux LEDs are used to illuminate the light guide.

Another feature of the invention is the ability to provide drawings andwritings in colors by incorporating photo-activated pigments or dyes inthe pressure-sensitive film, including fluorescent, luminescent,phosphorescent, and photochromic compounds. Each compound emits acertain colored light when exposed to light of the activatingwavelength, usually in the ultraviolet or infrared region. When thelight guide is illuminated by an LED of the activating wavelength for aspecific compound, pressure from the stylus on the drawing surface willextract light from the light guide into the film, thereby changing thevisible light emitted or reflected from that compound. Some of thesephoto-activated colors are seen by the user as reflected light, which isgenerally more soothing to the eye than emitted light from a lightguide. Depending on the duration of the deactivation time associatedwith these compounds, termination of the light source can erase thedrawing or writing.

Another feature of the invention is the use of a stylus or otherpressure-applying and non-transferring pen used as a marking instrument.

Another feature of the invention is that any drawing or writing can beerasable. Erasure is accomplished by breaking the bonds between thelight guide and the light-extracting film, such as by peeling away thefilm from the light guide or by other means. Erasure of drawings orwritings on a fluorescent or photochromic film can also be accomplishedby turning off the LED light source. For certain phosphorescent andphotochromic films, using LEDs of deactivating wavelengths will alsoerase the drawings or writings on the film. Using only a stylus andbeing erasable makes the invention very easy to operate.

Another feature of the invention is that it can be made into a permanentpressure-sensitive paper by ensuring that the bonds created between thefilm and its companion light guide or backlight are permanent.

Another feature of the invention is that it allows easy insertion ofbackground designs. By using a transparent pressure-sensitive film and atransparent light guide or backlight, an inserted background designsheet is visible to the user.

Another feature of the invention is that it is thin and lightweight inconstruction. This is achieved by using light ray modeling software todesign the light guide, films, and high-flux LEDs.

Another feature of the invention is the low cost of manufacturing.Plastic injection molding allows high quality and low cost manufacturingof optical components, such as the present light guide and films, whilemaintaining the surface characteristics required to create TotalInternal Reflection, the property that minimizes light loss prior tolight being extracted into the pressure-sensitive film. Continualimprovements in LED technology have resulted in brighter LEDs at lowercost.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of the present invention showing its majorcomponents.

FIG. 2 is a side view showing the light guide with reflectors and othercomponents.

FIG. 3 is a side view showing a two-sided light guide.

FIG. 4 is a side view showing the diffusing surface formed by a bondbetween the light-extracting film and the light guide.

FIG. 5 is a side view showing the three layers of a light-extractingfilm with micro-bumps.

FIG. 6 is a side view showing a light guide with a diffusing uppersurface and a layer of gel having an index of refraction sufficient tomaintain TIR within the light guide.

FIG. 7 a is a side view showing a light-extracting film and a lightguide with a moldable lower surface disposed above a reflecting layerwith an upper surface of reflector ridges that promote light reflectioninto the light guide.

FIG. 7 b is a side view showing a light guide with a moldable lowersurface disposed above a reflecting layer with an upper surface ofreflector ridges that promote light reflection into the light guide.

FIG. 8 a-1, 8 a-2, and 8 a-3 are 3 side views of an elasticlight-extracting film and a composite light guide with an elastic uppersurface, a middle layer of gel, and a lower layer of thin flexible film.

FIG. 8 b-1, 8 b-2, and 8 b-3 are 3 side views of a composite light guidewith an elastic upper surface, a middle layer of gel, and a lower layerof thin flexible film.

FIG. 9 is a side view of a pressure-sensitive light-emitting “paper”.

FIG. 10 is a side view of a light-blocking film containing air bubbles.

FIG. 11 is a side view of a light-blocking film comprised of two layersof film with a layer of opaque viscous liquid disposed between the twolayers.

FIG. 12 is a top view of the present invention as a toy drawing tabletwith color buttons and stencil stamps.

DETAILED DESCRIPTION OF THE INVENTION, INCLUDING THE PREFERREDEMBODIMENT

Terminology

The terminology and definitions of the prior art are not necessarilyconsistent with the terminology and definitions of the presentinvention. Where there is a conflict, the following definitions apply.

“Adapter backlight”—A special backlight that attaches to the displaypanel of a Modular Graphic Display Device. The adapter backlight iscoupled to an array of light pipes of the display panel, therebyenabling the array of light pipes to provide edge illumination to theadapter backlight instead of the light guide of the Modular GraphicDisplay Device. A companion pressure-sensitive light-blocking film isdisposed on the adapter backlight.

“Adapter light guide”—A special light guide that attaches to the displaypanel of the Modular Graphic Display Device. The adapter light guide iscoupled to the array of light pipes of the display panel, therebyenabling the array of light pipes to provide edge illumination to theadapter light guide instead of the light guide of the Modular GraphicDisplay Device. A companion pressure-sensitive light-extracting film isdisposed above the adapter light guide.

“Backlight”—A light guide with a diffusing surface to promote lightemission. The backlight is generally illuminated by LEDs or Cold CathodeFluorescent Lamps.

“Light-blocking film”—A pliable multi-layered film disposed on thebacklight that enables light to be transmitted from the backlight whenpressure is applied to the film. A layer in the film that containsfluorescent, luminescent, phosphorescent, or photochromic compounds willtransmit and/or transform the transmitted light.

“Light-extracting film”—A pliable film disposed on the light guide thatenables light to be extracted from the light guide when pressure appliedto the film creates bonds between the light guide and the film. Thebonds serve as the only extraction points for light in the light guide.The film will generally contain multiple layers.

“Light guide”—A light-transmitting plate that channels propagated lightto illuminate the light-extracting film through bonds between the lightguide and the film. In the absence of a light-extracting film, a lightguide is a light-transmitting plate that channels propagated light to amarking surface through reflector ridges or reflective angles on anon-marking surface of the light guide. The light guide is preferablyedge-illuminated by LEDs, and made of plastic. The light guide maycontain a liquid or a gel.

“Light guide rim”—A four-sided light channel in contact with the fouredges of the light guide for channeling light from the LEDs to the fouredges of the light guide to facilitate uniform light extraction.

Operation

In the following detailed description of the invention, reference ismade to the accompanying drawings which form a part hereof, and in whichare shown, by way of illustration, specific embodiments in which theinvention may be practiced. It is to be understood that otherembodiments may be used, and structural changes may be made withoutdeparting from the scope of the present invention.

Referring now to the drawings, FIG. 1 shows the present invention 10comprised of a light source 12, light guide or backlight 14, markinginstrument 16, drawing surface 18, and a cardboard backing 19. Markinginstruments include a stylus or any other pressure-applying device,including a stamp or a print head, such as a dot matrix print head.

FIG. 2 shows a light guide 20 disposed on a cardboard backing 19.Between the light guide 20 and the light-extracting film 24 is a layerof air 22. Light can travel within a light guide made of plastic withoutemission due to the principal of Total Internal Reflection (TIR). Asmooth surface is required in a light guide to maintain TIR. A layer ofair between the light guide and the light-extracting film preserves thesmooth surface of the light guide and thus maintains TIR. A bond betweenthe light guide and the film breaks the smooth surface of the lightguide and results in light being extracted from the light guide. LEDs 97are either white light or of different colors. LEDs 97 are powered bypower source 98 providing edgewise illumination to light guide 20.Brightness can be varied by controlling the intensity of the lightsource.

The light guide is designed using light ray modeling software forminimum light loss and uniform brightness for specific LEDs as lightsources. The upper surface, or receiving surface, of the light guidebonds with the lower surface, or positioning surface, of thelight-extracting film to provide light extraction from the light guide.A sticky optical (light transmitting) layer, such as paraffin orsilicon, may be applied to the upper surface of the light guide.Alternatively, the sticky optical layer may be applied to the lowersurface of the light-extracting film. The lower surface of the lightguide may be reflective. A reflective layer may be formed by havingreflectors or a reflective texture 21, or a reflective coating, topromote light extraction and uniform illumination, or any structure thatsufficiently changes the angle of propagated light to exit from thelight guide. The light guide may be composed of a hard, solid or semisolid, optical (light transmitting) material.

The light guide can be transparent, semi-transparent, clear, colored, ormulti-colored. Coupling mechanisms with individual LEDs are provided foredge illumination of the light guide. This may include a light guide rimthat provides edge illumination to the light guide at all four edges tofacilitate uniform light extraction. The composition, thickness, andpliability of the light guide will vary depending on the intendedapplication. It is designed for low-cost manufacturing through plasticextrusion or injection molding.

When the light guide and light-extracting film are substantially clear,a rigid plate containing a background design for tracing may be placedbehind the light guide.

FIG. 3 shows a two-sided light guide 20 a for use in a two-sidedpressure-sensitive drawing tablet. Between the upper and lower half ofthe light guide is a cardboard backing 19 a. Light from LED 97, poweredby power source 98, is propagated between the two halves of the lightguide through reflectors 21 a at the two ends. A layer of air 22separates the two halves of the light guide from their respectivelight-extracting films 24. A slot may be provided for insertion of abackground design sheet. A two-sided drawing tablet is useful as anoutdoor sign or where a drawing or writing needs to be displayed inopposite directions.

FIG. 4 shows light being extracted from a light guide 20 through alight-extracting point 25. Such a light-extracting point is formed whenpressure from a stylus depresses the light-extracting film through thelayer of air 22 to form a bond with the light guide. The bond maintainsTIR within the light guide without incurring Fresnel light loss. In thisway, drawing on the tablet with a stylus has the effect of drawing linesof light.

FIG. 5 shows a light guide 20 disposed below a light-extracting filmcomprised of three layers. The upper layer 24 a of the film is designedto promote light emission through a diffusing surface. Alight-transmitting middle layer 24 b transmits and/or transforms and/ormanipulates extracted light. The lower layer 24 c is designed tomaintain a layer of air 22 between the light guide and thelight-extracting film in order to preserve TIR within the light guide.The lower layer adheres to the light guide upon application of pressureand extracts light from the light guide.

To maintain a layer of air between the light-extracting film and thelight guide, and to facilitate bonding between the film and the lightguide when pressure is applied from a stylus, the lower layer 24 c mayhave micro-bumps 26 or any other protruding or textured structure thatmaintains a layer of air between the film and the light guide. The lowerlayer may have a contact layer (in a multi-layer film) composed of anadhesive optical (light transmitting) material including pliableplastics, such as low-density polyethylene or any other material thatcan establish a temporary optical adhesion to the light guide, such as aparaffin or silicon compound.

In addition to micro-bumps, the lower layer 24 c may also havelight-extracting micro-dots to form the bonds between the film and thelight guide when pressure is applied from a stylus. The micro-dots maybe any protruding structure, in any arrangement, capable of extractinglight from a light guide. That is, the only bonds formed between thelight-extracting film and the light guide are the bonds formed betweenthe light-extracting micro-dots and the light guide. This will allowlight within the light guide to propagate past a line oflight-extracting micro-dot bonds, thereby providing sufficient light toother areas within the light guide where light can be extracted throughother micro-dot bonds formed in that area. Visually, the line of lightcreated when pressure is applied from a stylus is a “halftone” line, ora line of dots of light.

Drawings on the light-extracting film may be erased by breaking thebonds between the film and the light guide. There are many ways to breakthe bonds between the film and the light guide such as by peeling backthe film from the light guide, by a spring-loaded mechanism, by an airknife to lift the film, by a slider having a lifting blade under thefilm, and so forth. Alternatively, the drawing on the light-extractingfilm may be made permanent when a permanent or difficult-to-break bondis established between the film and the light guide.

To minimize line distortion when pressure is applied, thelight-extracting film may be composed of a hard plastic upper layer,such as polyester, plus one or more sub-layers to establish and maintainan optical adhesion to the light guide. The light-extracting film mayalso include a protective marking surface. The film may also contain anintegrated light guide via a permanent bonding between the film and thelight guide. The light-extracting film is designed for low-costmanufacturing through plastic extrusion, injection molding, or cast-filmprocess.

Other Embodiments

Another embodiment of the present invention is to use a light-extractingfilm with a middle layer 24 b containing one or more fluorescent,luminescent, phosphorescent, or photochromic compound, as shown in FIG.5. A distinct color and/or luminescence appears when the film is exposedto extracted light of activating wavelength, e.g. ultraviolet light.Disposed on this layer of film may be an optical bandpass filter thatblocks light of activating wavelength, e.g. ultraviolet light beingfiltered to prevent photochromic activation from exposure to sunlight.

Color change or luminescence in the film will be sustained as long asexposure to light of activating wavelength is maintained throughtemporary or permanent adhesion to the light guide. Adding a source ofvisible light to an existing light of activating wavelength willintensify and/or change the color of the resultant emitted light.Erasure is accomplished by breaking the bond between the light guide andthe light-extracting film, such as by peeling away the film from thelight guide or by other means. Erasure of drawings or writings on afluorescent or photochromic film can also be accomplished by turning offthe LED light source. For certain phosphorescent and photochromic films,using LEDs of deactivating wavelengths will also erase the drawing orwriting on the film.

Referring to FIG. 6, another embodiment of the present invention is touse a light guide 30 with a diffusing upper surface 32 above which isdisposed a layer of gel 34 with an index of refraction sufficient tomaintain TIR within the combined light guide 30 and layer of gel 34. Alayer of air 36, or other compressible material with an index ofrefraction sufficient to maintain TIR within the combined light guide 30and layer of gel 34 as a single layer, is disposed above layer of gel34, and below a light-extracting film 38. When there is no pressure onlight-extracting film 38, TIR is maintained within the combined lightguide 30 and layer of gel 34 as a single layer. When pressure is appliedto light-extracting film 38, a bond is formed between the lower surfaceof light-extracting film 38 and diffusing upper surface 32 of lightguide 30. The diffusing upper surface enhances light extraction from thelight guide.

Referring to FIG. 7 a, another embodiment of the present invention is tohave a reflecting layer 40 with a surface of reflector ridges 42. Alayer of air 44, or other compressible material with a low index ofrefraction sufficient to maintain TIR within light guide 46, is disposedbetween reflecting layer 40 and light guide 46. Disposed on light guide46 is a light-extracting film 48. The surface of light-extracting film48 in contact with light guide 46, is made of a material with an indexof refraction sufficient to maintain TIR within light guide 46.Alternatively, this surface of light-extracting film 48 may be aseparate layer. Light guide 46 is made of a moldable optical materialthat, under pressure, will conform to the shape of reflector ridges 42facing light guide 46. Applying pressure on light guide 46 will createreflector shapes on the surface of light guide 46 facing reflectorridges 42, thereby reflecting light upward through light guide 46.

Referring to FIG. 7 b, another embodiment of the present invention is tohave a reflecting layer 40 with an upper surface of reflector ridges 42.A layer of air 44, or other compressible material with a low index ofrefraction sufficient to maintain TIR within light guide 46, is disposedbetween reflecting layer 40 and light guide 46. In contrast to theembodiment in FIG. 7 a, the embodiment in FIG. 7 b contains nolight-extracting film. The light guide is made of a moldable opticalmaterial that, under pressure, will conform to the shape of reflectorridges 42 facing light guide 46. Applying pressure on light guide 46will create reflector shapes on a surface of light guide 46 facingreflector ridges 42, thereby reflecting light upward through light guide46. Light guide 46 may also include a protective marking surface.

Another embodiment of the present invention is shown in FIG. 8 a-1 wherean elastic light-extracting film 51 is disposed on a composite lightguide 50 comprised of an elastic layer 52, a layer of gel 54 with anindex of refraction sufficient to maintain TIR within the compositelight guide, and a layer of thin flexible film 58. Disposed within layerof gel 54 is a honeycombed grid or mesh of vertical support pins 56 thatcrumple when pressure is applied to elastic layer 52 of composite lightguide 50. Vertical support pins 56 are any device or structure capableof being compressed or crumpled. Referring to FIG. 8 a-2, when pressureis applied through a stylus to elastic light-extracting film 51 andlight guide layer 53, vertical support pins 57 crumple beneath the areawhere the stylus applies pressure. Referring to FIG. 8 a-3, when thestylus is lifted, elastic light-extracting film 51 and light guide layer52 substantially return to their original un-compressed shape. Thiscauses flexible film 58 to form a crimp 59 or light reflective angle,thereby reflecting light upward through light guide 50.

Another embodiment of the present invention is shown in FIG. 8 b-1 wherea composite light guide 50 is comprised of an elastic layer 52, a layerof gel 54 with an index of refraction sufficient to maintain TIR withincomposite light guide 50, and a lower layer of thin flexible film 58. Incontrast to the embodiment in FIG. 8 a-1, the embodiment in FIG. 8 b-1contains no light-extracting film. Disposed within layer of gel 54 is ahoneycombed grid or mesh of vertical support pins 56 that crumple whenpressure is applied to the elastic layer 52 of the light guide 50.Referring to FIG. 8 b-1, when pressure is applied through a stylus tolayer 53, vertical support pins 57 crumple beneath the area where thestylus applies pressure. Referring to FIG. 8 b-2, when the stylus islifted, elastic layer 52 returns substantially to its originalun-compressed shape. This causes the flexible film to form a crimp 59 orlight reflective angle, thereby reflecting light upward through lightguide 50. Light guide 50 may also include a protective marking surface.

Another embodiment is to make the drawing surface a light guide paper 60as shown in FIG. 9. A light guide “paper” is a relatively thin markingor writing medium made with a light guide or a backlight. Since lightguides and backlights can be as thin as several millimeters or less,such a marking medium, in appearance and use, can be similar to a pieceof paper. This paper may be constructed very thin and flexible, or maybe constructed as a rigid sheet composed of a light guide 64 integratedwith a light-extracting film 68. A cardboard backing 62, or other rigidmaterial, may be used to support the paper. TIR is maintained withinlight guide 64 by inflating or trapping air 66 between light guide 64and the light-extracting film 68. The paper may be colored, and maycontain fluorescent, luminescent, phosphorescent, or photochromiccompounds. Special tablets are designed to hold sheets of paper, or aroll of paper, and to provide a coupling mechanism with LEDs for edgeillumination. When the paper is substantially clear, a rigid platecontaining a background design for tracing may be placed behind thelight guide paper, or between sheets of paper in a tablet. The paper mayalso include a protective marking surface. The paper is designed forlow-cost manufacturing through plastic extrusion or cast-film process.

Another embodiment is to use a backlight and a companion light-blockingfilm in place of a light guide and a companion light-extracting film. Abacklight is a light guide with a diffusing upper surface to promotelight emission. The backlight is generally illuminated by LEDs or ColdCathode Fluorescent Lamps. FIG. 10 shows a backlight 70 supported by acardboard backing 72. Disposed on the backlight is a light-blocking film74. Such a combination may be constructed as a relatively thin writingor marking medium that can be described as a paper.

When pressure is applied and the light-blocking film 74 is compressed,light is transmitted from the backlight due to a change in the film fromopaque or semi-opaque to transparent or semi-transparent. Thus adhesionis not required to transmit light, and a backlight is used instead of alight guide. The non-adhesive pressure-sensitive light-blocking film maybe colored, and may contain fluorescent, luminescent, phosphorescent, orphotochromic compounds.

An example of a light-blocking film containing air bubbles 74 is shownin FIG. 10. Applying pressure on the film with a stylus will break theair bubbles and allow light to be transmitted from the backlight throughthe film.

Another example of a light-blocking film is shown in FIG. 11 where alight guide 70 is supported by a cardboard backing 72. Thelight-blocking film is comprised of two layers of film, 76 and 78, witha layer of opaque gel 77 disposed between the two layers. Applyingpressure on the film with a stylus will disperse or move the opaque geland allow light to be transmitted from the backlight through the film.

Another embodiment is to make any of the previous embodiments a drawingtablet add-on to the display device described in U.S. patent application10/939,203 titled “Modular Graphic Display Device” filed on Sep. 10,2004. This add-on provides a pressure-sensitive means to draw or writewith a stylus or other pressure-applying device on a Modular GraphicDisplay Device by extracting light from an adapter light guide (asdefined above) or by permitting light to be transmitted from an adapterbacklight (as defined above). The add-on is comprised of any of: 1) anadapter light guide and a companion adhesive pressure-sensitivelight-extracting film, 2) an adapter light guide with reflector ridges,3) an adapter light guide with an elastic marking layer, or 4) anadapter backlight and a companion non-adhesive pressure-sensitivelight-blocking film. The adapter light guide and its companion adhesivepressure-sensitive light-extracting film has the same planar dimensions,which can vary from the size of one tile to the size of the entire lightguide plate. Likewise, the adapter light guide with reflector ridges,adapter light guide with an elastic marking layer, and adapter backlightand its companion non-adhesive pressure-sensitive light-blocking filmwill have the same planar dimensions, which can vary from the size ofone tile to the size of the entire light guide plate. After insertingthe drawing tablet add-on onto the light guide plate of a ModularGraphic Display Device, a user can create a drawing or writing on thepressure-sensitive film. A user may insert tiles together with thedrawing tablet add-on on the same light guide plate. For example, anadd-on containing a caricature drawing of a person may be placed at thecenter of the light guide plate with colored tiles serving as mattingaround the add-on drawing.

Another embodiment is to make the present invention a toy drawingtablet. FIG. 12 gives a top view of a toy drawing tablet 80 comprised ofa drawing surface 82, a background design 84 disposed behind drawingsurface 82, color buttons 86, stencil stamps 88, and a color intensityswitch 90. Each color button turns on an LED of a specific color.Stencil stamps are used to create drawings of different shapes tocomplement drawings made with the stylus 92. The background design maycontain alphabets and numerals for children to trace. Other designs maycontain drawings of popular toy figures, book characters, and heroesfrom comic books, cartoons, and movies.

As a way to attract attention to a drawing or writing, a separate powercontrol device can be used to control the light source for the drawing.This power control device can cause the drawing to blink randomly or atprescribed time intervals.

It is to be understood that the above descriptions and embodiments areintended to be illustrative, and not restrictive. Additional embodimentswill be apparent to those of skill in the art upon reviewing the abovedescriptions. The scope of the invention should, therefore, bedetermined with reference to the following claims, along with the fullscope of equivalents to which such claims are entitled.

1. A pressure-sensitive light-extracting paper for making illuminatedmarkings, said light-extracting paper comprising: a substantially thinlight guide operable to receive light from a light source; and alight-extracting film integrated with said light guide, thereby forminga composite, wherein said light-extracting film is adapted to adhere tosaid light guide upon application of pressure from a marking instrument,thereby extracting light from said light guide.
 2. The light-extractingpaper of claim 1, wherein said composite is flexible.
 3. Thelight-extracting paper of claim 1, wherein said composite issubstantially rigid.
 4. The light-extracting paper of claim 1, whereinsaid composite is adapted to support a layer of air between said lightguide and said light extracting film.
 5. The light-extracting paper ofclaim 1, wherein said light-extracting film includes a protectivemarking surface.
 6. The light-extracting paper of claim 1, wherein saidlight-extracting film includes light-extracting micro-dots on a surfacefacing said light guide.
 7. The light-extracting paper of claim 1,wherein said composite is adapted to support a layer of gel between saidlight guide and said light extracting film, wherein said layer of gelhas an index of refraction sufficient to maintain total internalreflection within said light guide.
 8. The light-extracting paper ofclaim 1, wherein said light guide has a diffusing surface facing saidlight-extracting film and said composite is adapted to support a layerof gel between said light guide and said light extracting film, whereinsaid layer of gel has an index of refraction sufficient to maintaintotal internal reflection within said light guide.
 9. Thelight-extracting paper of claim 1, wherein said composite issubstantially clear.
 10. The light-extracting paper of claim 1, whereinsaid light-extracting film contains a photo-activated compound selectedfrom the group consisting of fluorescent compound, luminescent compound,phosphorescent compound, and photochromic compound.
 11. Thelight-extracting paper of claim 1, wherein said light-extracting film isoperable to permanently adhere to said light guide upon pressure from amarking instrument.
 12. The light-extracting paper of claim 1, whereinsaid light-extracting film contains a band-pass filter.
 13. Thelight-extracting paper of claim 1, wherein said light guide is operableto receive light from a light source comprising one or more lightemitting diodes.
 14. The light-extracting paper of claim 1, wherein saidlight guide includes reflectors or a reflective texture, therebypromoting light extraction and uniform illumination.
 15. Thelight-extracting paper of claim 1, wherein said light guide has areflective coating, thereby promoting light extraction and uniformillumination.
 16. The light-extracting paper of claim 1, furthercomprising a sheet tablet for receiving sheets of said composite and forproviding edge illumination to said light guide of said composite. 17.The light-extracting paper of claim 1, further comprising a roll tabletfor holding a roll of said composite and for providing edge illuminationto said light guide of said composite.
 18. The light-extracting paper ofclaim 1, further comprising a sheet tablet for receiving sheets of saidcomposite and for providing edge illumination to said light guide ofsaid composite; and a rigid plate for separating sheets of saidcomposite and for holding background designs for tracing on said sheettablet.
 19. The light-extracting paper of claim 1, further comprising aroll tablet for holding a roll of said composite and for providing edgeillumination to said light guide of said composite; and a rigid platefor holding background designs for tracing on said roll tablet.
 20. Apressure-sensitive light-diffusing paper for making illuminatedmarkings, said light-diffusing paper comprising: a substantially thinbacklight having a light-diffusing surface operable to receive lightfrom a light source; and a light-blocking film integrated with saidbacklight, thereby forming a composite, wherein applying pressure tosaid light-blocking film with a marking instrument compresses saidlight-blocking film, creating visible markings where said light-blockingfilm has been compressed.
 21. The light-diffusing paper of claim 20,wherein said composite is flexible.
 22. The light-diffusing paper ofclaim 20, wherein said composite is substantially rigid.
 23. Thelight-diffusing paper of claim 20, wherein said composite includes aprotective marking surface.
 24. The light-diffusing paper of claim 20,wherein said backlight is operable to receive light from a light sourcecomprising one or more light emitting diodes.
 25. The light-diffusingpaper of claim 20, wherein said light-blocking film contains a layer ofsubstantially opaque gel.
 26. The light-diffusing paper of claim 20,wherein said light-blocking film contains a layer of breakable airbubbles.
 27. The light-diffusing paper of claim 20, wherein saidlight-blocking film includes a band-pass filter.
 28. The light-diffusingpaper of claim 20, wherein said light-blocking film contains aphoto-activated compound selected from the group consisting offluorescent compound, luminescent compound, phosphorescent compound, andphotochromic compound.
 29. The light-diffusing paper of claim 20,wherein stopping light from a light source connected to said backlightwill cause visible markings on said light-blocking film to begindisappearing.
 30. The light-diffusing paper of claim 20, wherein saidlight-blocking film permanently adheres to said backlight when pressureis applied to said light-blocking film with a marking instrument. 31.The light-diffusing paper of claim 20, further comprising a sheet tabletfor receiving sheets of said composite and for providing edgeillumination to said backlight of said composite.
 32. Thelight-diffusing paper of claim 20, further comprising a roll tablet forholding a roll of said composite and for providing edge illumination tosaid backlight of said composite.
 33. The light-diffusing paper of claim20, further comprising a sheet tablet for receiving sheets of saidcomposite and for providing edge illumination to said backlight of saidcomposite; and a rigid plate for separating sheets of said composite.34. A pressure-sensitive light-extracting device for making illuminatedmarkings, said device comprising: a light guide operable to receivelight from a light source, wherein said light guide has a receivingsurface for receiving a light-extracting film; and a light-extractingfilm positionable on said receiving surface of said light guide suchthat applying pressure to said light-extracting film with a markinginstrument causes a positioning surface of said light-extracting film toadhere to said receiving surface of said light guide, thereby extractinglight from said light guide.
 35. The light-extracting device of claim34, wherein said device is adapted to support a layer of air betweensaid light guide and said light-extracting film.
 36. Thelight-extracting device of claim 34, wherein said light-extracting filmincludes a protective marking surface.
 37. The light-extracting deviceof claim 34, wherein said light-extracting film contains includeslight-extracting micro-dots on a surface of said light-extracting filmfacing said light guide.
 38. The light-extracting device of claim 34,wherein said device is adapted to support a layer of gel between saidlight guide and said light-extracting film, wherein said layer of gelhas an index of refraction sufficient to maintain total internalreflection within said light guide.
 39. The light-extracting device ofclaim 34, wherein said device is adapted to support a layer of gelbetween said light guide and said light-extracting film, wherein saidlayer of gel has an index of refraction sufficient to maintain totalinternal reflection within said light guide, and said light guide has adiffusing surface facing said light-extracting film.
 40. Thelight-extracting device of claim 34, wherein said light guide and saidlight-extracting film are both substantially clear.
 41. Thelight-extracting device of claim 34, wherein said light-extracting filmcontains a photo-activated compound selected from the group consistingof fluorescent compound, luminescent compound, phosphorescent compound,and photochromic compound.
 42. The light-extracting device of claim 34,wherein said light-extracting film contains a band-pass filter.
 43. Thelight-extracting device of claim 34, wherein said positioning surface ofsaid light-extracting film contains micro-bumps for facilitating a layerof air between said light guide and said light extracting film.
 44. Thelight-extracting device of claim 34, wherein said light-extracting filmis operable to separate adhesive bonds between said light guide and saidlight-extracting film, thereby erasing visible markings on saidlight-extracting film.
 45. The light-extracting device-of claim 34,wherein-said-positioning surface-of said light-extracting filmpermanently adheres to said receiving surface of said light guide uponapplication of pressure on said light-extracting film.
 46. Thelight-extracting device of claim 34, wherein said light guide has twoopposite facing surfaces, both for receiving said light-extraction film.47. The light-extracting device of claim 34, wherein said light guide isoperable to receive light from one or more light emitting diodes. 48.The light-extracting device of claim 34, wherein said light guide isoperable to receive light from a light guide rim comprised of aplurality of light pipes optically coupled to one or more light emittingdiodes.
 49. The light-extracting device of claim 34, wherein a surfaceof said light guide is reflective.
 50. The light-extracting device ofclaim 34, further comprising a rigid plate for separating sheets and forholding background designs for tracing.
 51. The light-extracting deviceof claim 34, further comprising color control for changing color oflight from a light source.
 52. The light-extracting device of claim 34,further comprising light intensity control for varying brightness oflight from a light source.
 53. A pressure-sensitive light-extractingcomposite for making illuminated markings, said light-extractingcomposite comprising: a light guide operable to receive light from alight source; and a reflecting layer disposed on said light guidethereby forming a composite, wherein said reflecting layer has reflectorridges facing said light guide.
 54. The light-extracting composite ofclaim 53, wherein said composite is flexible.
 55. The light-extractingcomposite of claim 53, wherein said composite is substantially rigid.56. The light-extracting composite of claim 53, wherein said compositeincludes a protective marking surface.
 57. The light-extractingcomposite of claim 53, further comprising a light-extracting filmdisposed on said light guide.
 58. The light-extracting composite ofclaim 53, wherein said composite is substantially clear.
 59. Thelight-extracting composite of claim 53, wherein said light guide has amoldable surface facing said reflector ridges
 60. The light-extractingcomposite of claim 53, wherein said light guide has a moldable surfacefacing said reflector ridges, and said composite is adapted to support alayer of air between said light guide and said reflecting layer.
 61. Thelight-extracting composite of claim 53, wherein said light guide has amoldable surface facing said reflector ridges, and said composite isadapted to support a layer of gel between said light guide and saidreflecting layer.
 62. The light-extracting composite of claim 53,wherein said light guide is operable to receive light from a lightsource comprising one or more light emitting diodes.
 63. Thelight-extracting composite of claim 53, further comprising a sheettablet for receiving sheets of said composite and for providing edgeillumination to said light guide of said composite.
 64. Thelight-extracting composite of claim 53, further comprising a roll tabletfor holding a roll of said composite and for providing edge illuminationto said light guide of said composite.
 65. The light-extractingcomposite of claim 53, further comprising a sheet tablet for receivingsheets of said composite and for providing edge illumination to saidlight guide of said composite; and a rigid plate for separating sheetsof said composite and for holding background designs for tracing on saidsheet tablet.
 66. The light-extracting composite of claim 53, furthercomprising a roll tablet for holding a roll of said composite and forproviding edge illumination to said light guide of said composite; and arigid plate for holding background designs for tracing on said rolltablet.
 67. The light-extracting composite of claim 53, wherein saidlight guide is operable to receive light from a light guide rimcomprised of a plurality of light pipes optically coupled to one or morelight emitting diodes.
 68. The light-extracting composite of claim 53,further comprising a rigid plate for holding background designs fortracing.
 69. The light-extracting composite of claim 53, furthercomprising color control for changing color of light from a lightsource.
 70. The light-extracting composite of claim 53, furthercomprising light intensity control for varying brightness of light froma light source.
 71. A pressure-sensitive light-extracting composite formaking illuminated markings, said composite comprising: an elasticmarking layer; a light guide, said light guide containing an array ofsupport pins capable of being crumpled with application of pressure,said light guide containing a gel with an index of refraction sufficientto maintain total internal reflection within said light guide, whereinsaid elastic marking layer is disposed on said light guide; and acrimping film layer, wherein said light guide is disposed on saidcrimping film layer.
 72. The light-extracting composite of claim 71,wherein said composite includes a protective marking surface.
 73. Thelight-extracting composite of claim 71, wherein said composite issubstantially clear.
 74. The light-extracting composite of claim 71,further comprising a light-extracting film disposed on said elasticmarking layer.
 75. The light-extracting composite of claim 71, whereinsaid light guide is operable to receive light from a light sourcecomprising one or more light emitting diodes.
 76. The light-extractingcomposite of claim 71, wherein said light guide is operable to receivelight from a light guide rim comprised of a plurality of light pipesoptically coupled to one or more light emitting diodes.
 77. Thelight-extracting composite of claim 71, further comprising a rigid platefor holding background designs for tracing.
 78. The light-extractingcomposite of claim 71, further comprising color control for changingcolor of light from a light source.
 79. The light-extracting compositeof claim 71, further comprising light intensity control for varyingbrightness of light from a light source.
 80. The light-extractingcomposite of claim 71, further comprising a sheet tablet for receivingsheets of said composite and for providing edge illumination to saidlight guide of said composite.
 81. The light-extracting composite ofclaim 71, further comprising a roll tablet for holding a roll of saidcomposite and for providing edge illumination to said light guide ofsaid composite.
 82. The light-extracting composite of claim 71, furthercomprising a sheet tablet for receiving sheets of said composite and forproviding edge illumination to said light guide of said composite; and arigid plate for separating sheets of said composite and for holdingbackground designs for tracing on said sheet tablet.
 83. Thelight-extracting composite of claim 71, further comprising a roll tabletfor holding a roll of said composite and for providing edge illuminationto said light guide of said composite; and a rigid plate for holdingbackground designs for tracing on said roll tablet.
 84. Apressure-sensitive light-diffusing device for making illuminatedmarkings, said light-diffusing device comprising: a backlight operableto receive light from a light source and having a light-diffusingsurface, wherein said backlight is adapted to receive a light-blockingfilm on said light-diffusing surface; and a repositionable, compressablelight-blocking film for use with said backlight such that when saidlight blocking film is positioned on said light-diffusing surface,applying pressure to said light-blocking film with a marking instrumentcompresses said light-blocking film, causing light to be transmittedfrom said light-diffusing surface of said backlight into saidlight-blocking film, thereby creating illuminated markings where saidlight-blocking film has been compressed.
 85. The light-diffusing deviceof claim 84, wherein said light-blocking film includes a protectivemarking surface.
 86. The light-diffusing device of claim 84, whereinsaid backlight is operable to receive light from one or more lightemitting diodes.
 87. The light-diffusing device of claim 84, whereinsaid light-blocking film contains a layer of substantially opaque gel.88. The light-diffusing device of claim 84, wherein said light-blockingfilm contains a layer of breakable air bubbles.
 89. The light-diffusingdevice of claim 84, wherein said light-blocking film includes a bandpass filter.
 90. The light-diffusing device of claim 84, wherein saidlight-blocking film contains a photo-activated compound selected fromthe group consisting of fluorescent compound, luminescent compound,phosphorescent compound, and photochromic compound.
 91. Thelight-diffusing device of claim 84, wherein said light-blocking filmcontains a photo-activated compound such that stopping light from saidbacklight will cause illuminated markings on said light-blocking film tobegin disappearing.
 92. The light-diffusing device of claim 84, whereinsaid backlight is double-sided having two opposite facing surfaces forreceiving said light-blocking film.
 93. The light-diffusing device ofclaim 84, further comprising a rigid plate for separating sheets forsaid device.
 94. The light-diffusing device of claim 84, wherein saidbacklight further comprises a color control for changing color of saidbacklight.
 95. The light-diffusing device of claim 84, wherein saidbacklight further comprises a light intensity control for varyingbrightness of said backlight.
 96. A pressure-sensitive light-extractingtoy for making illuminated markings, said toy comprising: a light guideoperable to receive light from a light source, wherein said light guidehas a receiving surface for receiving a light-extracting film; and alight-extracting film positionable on said receiving surface of saidlight guide such that applying pressure to said light-extracting filmwith a marking instrument causes a positioning surface of saidlight-extracting film to adhere to said receiving surface of said lightguide, thereby extracting light from said light guide.
 97. Thelight-extracting toy of claim 96, wherein said toy is adapted to supporta layer of air between said light guide and said light-extracting film.98. The light-extracting toy of claim 96, wherein said light guideincludes an protective marking layer.
 99. The light-extracting toy ofclaim 96, wherein said light-extracting film contains light-extractingmicro-dots on a surface of said light-extracting film, said surfacefacing said light guide.
 100. The light-extracting toy of claim 96,wherein said toy is adapted to support a layer of gel on said receivingsurface of said light guide, where said layer of gel has an index ofrefraction sufficient to maintain total internal reflection within saidlight guide.
 101. The light-extracting toy of claim 96, wherein saidreceiving surface is a light-diffusing surface.
 102. Thelight-extracting toy of claim 96, wherein said light guide and saidlight-extracting film are both substantially clear.
 103. Thelight-extracting toy of claim 96, wherein said light-extracting filmcontains a photo-activated compound selected from the group consistingof fluorescent compound, luminescent compound, phosphorescent compound,and photochromic compound.
 104. The light-extracting toy of claim 96,wherein said light-extracting film contains a band-pass filter.
 105. Thelight-extracting toy of claim 96, wherein said positioning surface ofsaid light-extracting film contains micro-bumps for facilitating a layerof air between said light guide and said light extracting film.
 106. Thelight-extracting toy of claim 96, wherein said light-extracting film isoperable to separate adhesive bonds between said light guide and saidlight-extracting film, thereby erasing visible markings on saidlight-extracting film.
 107. The light-extracting toy of claim 96,wherein said positioning surface of said light-extracting filmpermanently adheres to said receiving surface of said light guide uponapplication of pressure on said light-extracting film.
 108. Thelight-extracting toy of claim 96, wherein said light guide has twoopposite facing surfaces for receiving said light-extraction film. 109.The light-extracting toy of claim 96, wherein said light guide isoperable to receive light from one or more light emitting diodes. 110.The light-extracting toy of claim 96, wherein said light guide isoperable to receive light from a light guide rim comprised of aplurality of light pipes optically coupled to one or more light emittingdiodes.
 111. The light-extracting toy of claim 96, wherein said lightguide includes reflectors or a reflective texture, thereby promotinglight extraction and uniform illumination.
 112. The light-extracting toyof claim 96, wherein said light guide has a reflective coating, therebypromoting light extraction and uniform illumination.
 113. Thelight-extracting toy of claim 96, further comprising a stylus.
 114. Thelight-extracting toy of claim 96, further comprising stencil stamps.115. The light-extracting toy of claim 96, further comprising a rigidplate for separating sheets and for holding background designs fortracing.
 116. The light-extracting toy of claim 96, further comprisingcolor control for changing color of light from a light source.
 117. Thelight-extracting toy of claim 96, further comprising light intensitycontrol for varying brightness of light from a light source.
 118. Thelight-extracting toy of claim 96, further comprising control for causingsaid light source to blink.
 119. A pressure-sensitive light-extractingtoy for making illuminated markings, said light-extracting toycomprising: a light guide operable to receive light from a light source;and a reflecting layer disposed on said light guide thereby forming acomposite, wherein said reflecting layer has reflector ridges facingsaid light guide.
 120. The light-extracting toy of claim 119, whereinsaid composite includes a protective marking surface.
 121. Thelight-extracting toy of claim 119, wherein said composite issubstantially clear.
 122. The light-extracting toy of claim 119, whereinsaid light guide has a moldable surface facing said reflector ridges123. The light-extracting toy of claim 119, wherein said light guide hasa moldable surface facing said reflector ridges, and said composite isadapted to support a layer of air between said light guide and saidreflecting layer.
 124. The light-extracting toy of claim 119, whereinsaid light guide has a moldable surface facing said reflector ridges,and said composite is adapted to support a layer of gel between saidlight guide and said reflecting layer.
 125. The light-extracting toy ofclaim 119, wherein said light guide is operable to receive light from alight source comprising one or more light emitting diodes.
 126. Thelight-extracting toy of claim 119, wherein said light guide is operableto receive light from a light guide rim comprised of a plurality oflight pipes optically coupled to one or more light emitting diodes. 127.The light-extracting toy of claim 119, further comprising a stylus. 128.The light-extracting toy of claim 119, further comprising stencilstamps.
 129. The light-extracting toy of claim 119, further comprising arigid plate for separating sheets and for holding background designs fortracing.
 130. The light-extracting toy of claim 119, further comprisingcolor control for changing color of light from a light source.
 131. Thelight-extracting toy of claim 119, further comprising light intensitycontrol for varying brightness of light from a light source.
 132. Thelight-extracting toy of claim 119, further comprising control forcausing said light source to blink.
 133. A pressure-sensitivelight-extracting toy for making illuminated markings, said toycomprising: an elastic marking layer; a light guide, said light guidecontaining an array of support pins capable of being crumpled withapplication of pressure, said light guide containing a gel with an indexof refraction sufficient to maintain total internal reflection withinsaid light guide, wherein said elastic marking layer is disposed on saidlight guide; and a crimping film layer, wherein said light guide isdisposed on said crimping film layer.
 134. The light-extracting toy ofclaim 133, wherein said composite includes a protective marking surface.135. The light-extracting toy of claim 133, wherein said composite issubstantially clear.
 136. The light-extracting toy of claim 133, whereinsaid light guide is operable to receive light from a light sourcecomprising one or more light emitting diodes.
 137. The light-extractingtoy of claim 133, wherein said light guide is operable to receive lightfrom a light guide rim comprised of a plurality of light pipes opticallycoupled to one or more light emitting diodes.
 138. The light-extractingtoy of claim 133, further comprising a stylus.
 139. The light-extractingtoy of claim 133, further comprising stencil stamps.
 140. Thelight-extracting toy of claim 133, further comprising a rigid plate forholding background designs for tracing.
 141. The light-extracting toy ofclaim 133, further comprising color control for changing color of lightfrom a light source.
 142. The light-extracting toy of claim 133, furthercomprising light intensity control for varying brightness of light froma light source.
 143. The light-extracting toy of claim 133, furthercomprising control for causing said light source to blink.
 144. Apressure-sensitive light-diffusing toy for making illuminated markingscomprising: a backlight having a light-diffusing surface and operable toreceive light from a light source, wherein said backlight is adapted toreceive a light-blocking film on said light-diffusing surface; and arepositionable, compressable light-blocking film for use with saidbacklight such that when said light blocking film is positioned on saidlight-diffusing surface, applying pressure to said light-blocking filmwith a marking instrument compresses said light-blocking film, causinglight to be transmitted from said light-diffusing surface of saidbacklight into said light-blocking film, thereby creating illuminatedmarkings where said light-blocking film has been compressed.
 145. Thetoy with backlight of claim 144, wherein said light-blocking filmincludes a protective marking surface.
 146. The toy with backlight ofclaim 144, wherein said backlight is operable to receive light from oneor more light emitting diodes.
 147. The toy with backlight of claim 144,wherein said light-blocking film contains a layer of substantiallyopaque gel.
 148. The toy with backlight of claim 144, wherein saidlight-blocking film contains a layer of breakable air bubbles.
 149. Thetoy with backlight of claim 144, wherein said light-blocking filmincludes a band-pass filter.
 150. The toy with backlight of claim 144,wherein said light-blocking film contains a photo-activated compoundselected from the group consisting of fluorescent compound, luminescentcompound, phosphorescent compound, and photochromic compound.
 151. Thetoy with backlight of claim 144, wherein said light-blocking filmcontains a photo-activated compound such that stopping light from saidbacklight will cause illuminated markings on said light-blocking film tobegin disappearing.
 152. The toy with backlight of claim 144, whereinsaid backlight has two opposite facing surfaces for receiving saidlight-blocking film.
 153. The toy with backlight of claim 144, furthercomprising a stylus.
 154. The toy with backlight of claim 144, furthercomprising stencil stamps.
 155. The toy with backlight of claim 144,further comprising a rigid plate for separating sheets for said device.156. The toy with backlight of claim 144, wherein said backlight furthercomprises a color control for changing color of said backlight.
 157. Thetoy with backlight of claim 144, wherein said backlight furthercomprises a light intensity control for varying brightness of saidbacklight.
 158. The toy with backlight of claim 144, wherein saidbacklight further comprises control for causing said backlight to blink.159. An add-on to a modular display device, said modular display devicecomprising a display panel having an array of light pipes, coupled tolight emitting diodes on a first end and coupled to a light guide onsaid display panel on a second end for providing edge illumination tosaid light guide on said display panel, said light guide add-oncomprising: an adapter light guide operable for attaching to saiddisplay panel of said modular display device to receive edgeillumination from said display panel, wherein said adapter light guidehas a receiving surface for receiving a light-extracting film; and alight-extracting film positionable on said adapter light guide such thatapplying pressure to said light-extracting film with a markinginstrument causes a positioning surface of said light-extracting film toadhere to said receiving surface of said adapter light guide, therebyextracting light from said adapter light guide.
 160. The light guideadd-on of claim 159, wherein said add-on is adapted to support a layerof air between said adapter light guide and said light-extracting film.161. The light guide add-on of claim 159, wherein said light-extractingfilm includes a protective marking surface.
 162. The light guide add-onof claim 159, wherein said light-extracting film containslight-extracting micro-dots on a surface of said light-extracting film,said surface facing said light guide.
 163. The light guide add-on ofclaim 159, wherein said add-on is adapted to support a layer of gel onsaid receiving surface of said light guide, where said layer of gel hasan index of refraction sufficient to maintain total internal reflectionwithin said light guide.
 164. The light guide add-on of claim 159,wherein said receiving surface is a light-diffusing surface.
 165. Thelight guide add-on of claim 159, wherein said light guide and saidlight-extracting film are both substantially clear.
 166. The light guideadd-on of claim 159, wherein said light-extracting film contains aphoto-activated compound selected from the group consisting offluorescent compound, luminescent compound, phosphorescent compound, andphotochromic compound.
 167. The light guide add-on of claim 159, whereinsaid light-extracting film contains a band-pass filter.
 168. The lightguide add-on of claim 159, wherein said positioning surface of saidlight-extracting film contains micro-bumps for facilitating a layer ofair between said adapter light guide and said light extracting film.169. The light guide add-on of claim 159, wherein said light-extractingfilm is operable to separate adhesive bonds between said adapter lightguide and said light-extracting film, thereby erasing visible markingson said light-extracting film.
 170. The light guide add-on of claim 159,wherein said positioning surface of said light-extracting filmpermanently adheres to said receiving surface of said adapter lightguide upon application of pressure on said light-extracting film. 171.The light guide add-on of claim 159, wherein said adapter light guideincludes reflectors or a reflective texture, thereby promoting lightextraction and uniform illumination.
 172. The light guide add-on ofclaim 159, wherein said adapter light guide has a reflective coating,thereby promoting light extraction and uniform illumination.
 173. Thelight guide add-on of claim 159, further comprising a stylus.
 174. Thelight guide add-on of claim 159, further comprising stencil stamps. 175.The light guide add-on of claim 159, further comprising a rigid platefor holding background designs for tracing.
 176. An add-on to a modulardisplay device, said modular display device comprising a display panelhaving an array of light pipes, coupled to light emitting diodes on afirst end and coupled to a light guide on said display panel on a secondend for providing edge illumination to said light guide on said displaypanel, said add-on comprising: an adapter light guide operable forattaching to said display panel of said modular display device toreceive edge illumination from said display panel through coupling tosaid second end of said array of light pipes of said modular displaydevice; and a reflecting layer disposed on said light guide adapter andintegrated with said adapter light guide, thereby forming a composite,wherein said reflecting layer has reflector ridges for promoting lightreflection into said adapter light guide.
 177. The light guide add-on ofclaim 176, wherein said composite includes a protective marking surface.178. The light guide add-on of claim 176, wherein said composite issubstantially clear.
 179. The light guide add-on of claim 176, whereinsaid adapter light guide has a moldable surface facing said reflectorridges
 180. The light guide add-on of claim 176, wherein said adapterlight guide has a moldable surface facing said reflector ridges, andsaid composite is adapted to support a layer of air between said adapterlight guide and said reflecting layer.
 181. The light guide add-on ofclaim 176, wherein said adapter light guide has a moldable surfacefacing said reflector ridges, and said composite is adapted to support alayer of gel between said adapter light guide and said reflecting layer.182. The light guide add-on of claim 176, further comprising a stylus.183. The light guide add-on of claim 176, further comprising stencilstamps.
 184. The light guide add-on of claim 176, further comprising arigid plate for holding background designs for tracing.
 185. An add-onto a modular display device, said modular display device comprising adisplay panel having an array of light pipes, coupled to light emittingdiodes on a first end and coupled to a light guide on said display panelon a second end for providing edge illumination to said light guide onsaid display panel, said add-on comprising: an adapter light guideoperable for attaching to said display panel of said modular displaydevice to receive edge illumination from said display panel of saidmodular display device, said adapter light guide containing an array ofsupport pins capable of being crumpled with application of pressure,said light guide containing a gel with an index of refraction sufficientto maintain total internal reflection within said light guide; anelastic elastic marking layer disposed on a first surface of saidadapter light guide; and a crimping film layer disposed on a secondsurface of said adapter light.
 186. The light guide add-on of claim 185,wherein said composite includes a protective marking surface.
 187. Thelight guide add-on of claim 185, wherein said composite is substantiallyclear.
 188. The light guide add-on of claim 185, further comprising astylus.
 189. The light guide add-on of claim 185, further comprisingstencil stamps.
 190. The light guide add-on of claim 185, furthercomprising a rigid plate for holding background designs for tracing.191. An add-on to a modular display device, said modular display devicecomprising a display panel having an array of light pipes, coupled tolight emitting diodes on a first end and coupled to a backlight on saiddisplay panel on a second end for providing edge illumination to saidbacklight on said display panel, said backlight add-on comprising: anadapter backlight operable for attaching to said display panel of saidmodular display device to receive edge illumination from said displaypanel of said modular display device, wherein said adapter backlight hasa light-diffusing surface for receiving a light-blocking film; and arepositionable, compressable light-blocking film for use with saidadapter backlight such that when said light-blocking film is positionedon said light-diffusing surface of said adapter backlight, applyingpressure to said light-blocking film with a marking instrumentcompresses said light-blocking film, causing light to be transmittedfrom said light-diffusing surface of said adapter backlight into saidlight-blocking film, thereby creating illuminated markings where saidlight-blocking film has been compressed.
 192. The backlight add-on ofclaim 191, wherein said light-blocking film includes a protectivemarking surface.
 193. The backlight add-on of claim 191, wherein saidlight-blocking film contains a layer of substantially opaque gel. 194.The backlight add-on of claim 191, wherein said light-blocking filmcontains a layer of breakable air bubbles.
 195. The backlight add-on ofclaim 191, wherein said light-blocking film includes a band-pass filter.196. The backlight add-on of claim 191, wherein said light-blocking filmcontains a photo-activated compound selected from the group consistingof fluorescent compound, luminescent compound, phosphorescent compound,and photochromic compound.
 197. The backlight add-on of claim 191,wherein said light-blocking film contains a photo-activated compoundsuch that stopping light from said adapter backlight will causeilluminated markings on said light-blocking film to begin disappearing.198. The backlight add-on of claim 191, further comprising a stylus.199. The backlight add-on of claim 191, further comprising stencilstamps.
 200. The backlight add-on of claim 191, further comprising arigid plate for separating sheets for said backlight add-on.
 201. Apressure-sensitive light-extracting toy for making illuminated markings,said toy comprising: a substantially clear light guide operable toreceive light from one or more light emitting diodes, wherein said lightguide has a receiving surface for receiving a light-extracting film; asubstantially clear light-extracting film positionable on said receivingsurface of said light guide such that applying pressure to saidlight-extracting film with a stylus causes a positioning surface of saidlight-extracting film to adhere to said receiving surface of said lightguide, thereby extracting light from said light guide, wherein saidlight-extracting film is repositionable on said light guide such thatrepositioning said light-extracting film erases any visible markings onsaid light-extracting film; light-extracting micro-dots on a surface ofsaid light-extracting film, said surface facing said light guide; one ormore light-emitting diodes for providing light to at least one edge ofsaid light guide; a light control for varying brightness of said one ormore light-emitting diodes; and a stylus.